1. Field of Invention
The present invention relates to wind turbine blades and more particularly to the production of a simple, extremely lightweight filament-reinforced blade of nonuniform wall thickness.
2. Description of the Prior Art
In the current press for new forms of energy sources, one attractive candidate has been the wind turbine. In general, a wind turbine comprises an arrangement of rotor blades, hub, pitch change mechanism, gear box, tower, generator and typically an electrical interface, all adapted to extreme energy from atmospheric winds and convert it into electrical or other useful forms of energy.
A key portion of the wind turbine is its extremely long rotor blades, which may be as long as 100 feet or more and which are subjected to severe bending and twisting at design loadings. Currently favored blade designs include fabrication by either the lay-up of separate composite panels or sheets or the multiple winding of individual filaments or bundles of filaments. One example of the latter technique is disclosed in U.S. Pat. No. 4,081,220 issued on Mar. 28, 1978 and owned by assignee common to the present invention, which disclosure is incorporated herein by reference.